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<p>Hi, Jagan,<br>
</p>
<div class="moz-cite-prefix">On 3/15/19 4:45 PM, Maxime Ripard
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:20190315134555.ekpywymjx3xqmdhf@flea">
<pre class="moz-quote-pre" wrap="">On Fri, Mar 15, 2019 at 02:32:55PM +0100, Paul Kocialkowski wrote:
</pre>
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">Hi,
On Fri, 2019-03-15 at 18:38 +0530, Jagan Teki wrote:
</pre>
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">Some display panels would come up with a non-DSI output which
can have an option to connect DSI interface by means of bridge
convertor.
This DSI to non-DSI bridge convertor would require a bridge
driver that would communicate the DSI controller for bridge
functionalities.
So, add support for bridge functionalities in Allwinner DSI
controller.
</pre>
</blockquote>
<pre class="moz-quote-pre" wrap="">
See a few comments below.
</pre>
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">Signed-off-by: Jagan Teki <a class="moz-txt-link-rfc2396E" href="mailto:jagan@amarulasolutions.com"><jagan@amarulasolutions.com></a>
---
drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 65 +++++++++++++++++++-------
drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h | 1 +
2 files changed, 49 insertions(+), 17 deletions(-)
diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
index 0960b96b62cc..64d74313b842 100644
--- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
+++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
@@ -781,6 +781,9 @@ static void sun6i_dsi_encoder_enable(struct drm_encoder *encoder)
if (!IS_ERR(dsi->panel))
drm_panel_prepare(dsi->panel);
+ if (!IS_ERR(dsi->bridge))
+ drm_bridge_pre_enable(dsi->bridge);
+
/*
* FIXME: This should be moved after the switch to HS mode.
*
@@ -796,6 +799,9 @@ static void sun6i_dsi_encoder_enable(struct drm_encoder *encoder)
if (!IS_ERR(dsi->panel))
drm_panel_enable(dsi->panel);
+ if (!IS_ERR(dsi->bridge))
+ drm_bridge_enable(dsi->bridge);
+
sun6i_dsi_start(dsi, DSI_START_HSC);
udelay(1000);
@@ -812,6 +818,9 @@ static void sun6i_dsi_encoder_disable(struct drm_encoder *encoder)
if (!IS_ERR(dsi->panel)) {
drm_panel_disable(dsi->panel);
drm_panel_unprepare(dsi->panel);
+ } else if (!IS_ERR(dsi->bridge)) {
+ drm_bridge_disable(dsi->bridge);
+ drm_bridge_post_disable(dsi->bridge);
}
phy_power_off(dsi->dphy);
@@ -973,11 +982,16 @@ static int sun6i_dsi_attach(struct mipi_dsi_host *host,
struct sun6i_dsi *dsi = host_to_sun6i_dsi(host);
dsi->device = device;
- dsi->panel = of_drm_find_panel(device->dev.of_node);
- if (IS_ERR(dsi->panel))
- return PTR_ERR(dsi->panel);
- dev_info(host->dev, "Attached device %s\n", device->name);
+ dsi->bridge = of_drm_find_bridge(device->dev.of_node);
+ if (!dsi->bridge) {
</pre>
</blockquote>
<pre class="moz-quote-pre" wrap="">
You are using IS_ERR to check that the bridge is alive in the changes
above, but switch to checking that it's non-NULL at this point.
Are both guaranteed to be interchangeable?
</pre>
</blockquote>
<pre class="moz-quote-pre" wrap="">
They aren't. Any ERR_PTR will be !NULL
</pre>
<blockquote type="cite">
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">+ dsi->panel = of_drm_find_panel(device->dev.of_node);
+ if (IS_ERR(dsi->panel))
+ return PTR_ERR(dsi->panel);
+ }
</pre>
</blockquote>
<pre class="moz-quote-pre" wrap="">
You should probably use drm_of_find_panel_or_bridge instead of
duplicating the logic here.
</pre>
</blockquote>
<pre class="moz-quote-pre" wrap="">
Or we can even use the drm_panel_bridge_add to simplify things.</pre>
</blockquote>
<p>this approach is implemented by E.Anholt in VC4 dsi driver and it
looks nice.<br>
</p>
<blockquote type="cite"
cite="mid:20190315134555.ekpywymjx3xqmdhf@flea">
<pre class="moz-quote-pre" wrap="">
Maxime
</pre>
<br>
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</pre>
</blockquote>
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